Patent GB-872306-A (GB)
Title: Epoxide compositions and their production
IPC: C08G59/42
Filed: 1958-04-03
Abstract: A curable composition comprises an epoxide having the general formula:  <FORM:0872306/IV (a)/1> wherein X is a divalent radical which is -CH2 O,CO-, or -CH2O,CO,R,CO,O,CH2- or -CO,O-R-O,CO-, R is an aliphatic or aromatic radical and R1 to R6 are hydrogen atoms or lower alkyl groups (i.e. containing 1-4 carbon atoms); and a polyol. As a modification a polycarboxylic compound is also present in the composition.  A preferred class of composition contains (a) a 3, 4-epoxy-cyclohexylmethyl 3, 4-epoxycyclohexane carboxylate with (b) a polyol, preferably a polyhydric phenol in amount having from 0,2-1,5 hydroxyl equivalents per epoxy equivalent.  The term "polyol" also includes compounds of the formula:  <FORM:0872306/IV (a)/2> in which R is an alkyl group or hydrogen, Z is a single bond or a divalent group composed of a carbon atom or group of carbon atoms to which there can be attached hydrogen, alkyl, hydroxyl, carboxyl or amino groups, or can represent an oxyalkylene or polyoxy alkylene group, or a sulphur containing group or may contain nitrogen to which hydrogen, alkyl or alkanol groups may be attached.  The R's and Z together with the C's can represent a cyclic group such as phenylene or cyclohexylene.  Polyhydric phenol-formaldehyde condensation products can also be used. "Polycarboxylic compound" means polycarboxylic anhydrides, acids and acid-esters.  The anhydrides may have the formula:  <FORM:0872306/IV (a)/3> wherein Y represents two or more carbon atoms interconnected single or double bonds to which there may be attached hydrogen, alkyl, hydroxyl, nitro, chloro, iodo, bromo or cyclic groups, or Y may represent an oxydicarboxyl or a cyclic group such as phenylene, cyclohexylene or cyclohexenylene, a list of such compounds being given.  Also specified are a number of aliphatic, aromatic and cycloaliphatic di- and tricarboxylic acids, acid-esters or polycarboxy polyesters are also specified, a list of suitable polyalcohols for reaction with di-, tri- or tetracarboxylic acids for this purpose being given.  Lists are also given of the three types of di-epoxides corresponding to the first general formula above.  The curable composition is prepared by heating at 25 DEG -250 DEG C. a mixture of the diepoxide and polyol with or without the polycarboxylic compound to give a gelated product.  As a catalyst for this stage, sulphuric acid, stannic chloride, perchloric acid, pyridine, aniline, benzyldimethylamine, benzyltrimethylammonium hydroxide and dilute sodium hydroxide are specified as catalysts. Curing of the gelated product is effected by further heating.  A catalyst such as strong alkalis, mineral acids and metal halide Lewis acids, which may be added in a solvent such as water, ethers, esters, ketones, or alcohols, is advantageously employed.  In typical examples (1) a mixture of 3, 4-epoxy-6-methylcyclohexylmethyl 3, 4-epoxy-6-methyl-cyclohexane carboxylate is heated with resorcinol to form a uniform melt which is cured by heating at 170 DEG C.; (9) a gel obtained by heating a mixture of the same diepoxide, diphenylol propane and adipic acid is cured by heating at 170 DEG C. (10) bis (3, 4-epoxy-cyclohexylmethyl oxalate and resorcinol are reacted similarly.